Actually, TWO things from Augustine (354 - 430), Bishop of Hippo. Both emphasize our utter dependence upon God to aid us in our Christian life. The first mentions God's grace to help us overcome temptation. The second mentions God's grace to work in us to do good works. Even in our Christian living, faith is useless unless God grants us the strength to live and act according to his will. Therefore, we flee to God's word and sacraments again and again so that the Lord will strengthen and keep us in the true Christian faith unto life everlasting.
“If our Saviour had only said, Watch that you enter not into temptation, He would appear to have done nothing further than admonish man's will; but since He added the words, and pray, He showed that God helps us not to enter into temptation.” (Augustine, Selections from “On Grace and Free Will,” chapter 9)
“Wherefore no man ought, even when he begins to possess good merits, to attribute them to himself, but to God, who is thus addressed by the Psalmist: Be Thou my helper, forsake me not. But saying, Forsake me not, he shows that if he were to be forsaken, he is unable of himself to do any good thing.” (Augustine, Selections from “On Grace and Free Will,” chapter 13)